Answer: C) 133
Step-by-step explanation:
The formula to find the sample size is given by :-

, where z* = Critical z-value
= Population standard deviation for prior study.
E= Margin of error.
As per given , we have
E= 5
The critical z-value for 90% confidence level is 1.645.
Substitute al;l the value sin the above formula , we get




Hence, the minimum sample size needed is 133.
Thus , the correct answer is : C) 133
Answer:
63.8 miles
Step-by-step explanation:
If the train travels 4.4 miles in 4 minutes, then you have to divide 4.4/4 to find the miles the train travels per minute.
4.4/4 = 1.1
So, since the train travels 1.1 miles per minute, and we want to know how fast it travels in 58 minutes, we have to multiply 1.1 by 58. Since 1.1 is a decimal number, we have to multiply both sides by 10 to get 11x580.
11x580 = 5800+ 580 = 6380
Since we multiplied both numbers by 10, we have to divide 6380 by 100.
6380/100 = 63.8
So, the train travels 63.8 miles in 58 minutes.
For this case we have the following expression:
(x ^ 2 + 2x + 1 / x ^ 2-8x + 16) / (x + 1 / x ^ 2-16)
Rewriting we have:
(((x + 1) (x + 1)) / ((x-4) (x-4))) / (x + 1 / ((x + 4) (x-4)))
Then, we cancel similar terms:
((x + 1) / (x-4)) / (1 / (x + 4))
Rewriting:
((x + 1) (x + 4)) / (x-4)
Answer:
((x + 1) (x + 4)) / (x-4)
I think it only surrounds 1 meter because it’s a meter long